Data storage medium and method for contactless communication between the data storage medium and a reader

ABSTRACT

A method and a data carrier for contactless communication of a reading device with at least two communication-ready applications located on a portable data carrier. A first communication-readiness signal is generated for a first application and sent to the reading device, the signal having a first identification number that is assigned to the first application and indicates to the reading device the communication readiness of said first application, and a second communication-readiness signal is generated and sent for a second application, the second signal having a second identification number different from the first identification number, which is assigned to said second application and indicates to the reading device the communication readiness of the second application. The identification numbers simulate for the reading device the communication readiness of a data carrier in each case. The reading device thus has the impression of communicating with applications of two separate data carriers.

FIELD OF INVENTION

The present invention relates to a method for contactless communicationof at least two applications stored on a common portable data carrierwith a reading device, and to an accordingly set up data carrier. A datacarrier according to the invention may be e.g. a contactlesslycommunicating chip card, a contactlessly communicating label, acontactlessly communicating identification document, a security moduleSAM (secure application module) equipped for contactless communication,or an electronic device, such as a mobile terminal with an NFCinterface, equipped for contactless communication.

BACKGROUND

In the prior art (e.g. Finkenzeller, Klaus: RFID-Handbuch, Munich, 2002)there are described various contactlessly communicating data carriers,for example chip cards and RFID transponders (radio frequencyidentification transponders), e.g. according to the standard ISO/IEC14443. These are so-called proximity coupling chip cards, which arefrequently used in the application field of ticketing, that is, aspublic transport tickets for example. The energy supply to the datacarrier is normally effected here by the magnetic alternating field of areading device. The range of such a data carrier is approx. 7 to 15 cm.The invention is not restricted to transponder chip cards with suchshort ranges, however, but can also be used in connection with othercontactlessly communicating data carriers with other ranges and/oraccording to other standards. It is fundamentally also possible to usedata carriers with their own energy source.

When such a data carrier is brought into the response field of a readingdevice, thereby commencing its energy supply and putting it in anoperational mode, it can receive a search signal emitted cyclically bythe reading device and indicate its communication readiness to thereading device by means of a first response signal. As soon as thereading device has received this signal it starts a selection processusing a so-called anti-collision method in order to specifically selectone data carrier for further communication when a plurality ofcommunication-ready data carriers are located in the response field ofthe reading device at the same time. However, there are also readingdevices that communicate via proprietary, nonstandard communicationsprotocols and do not support any anti-collision methods.

The selection of a data carrier is effected in the case of ananti-collision method on the basis of a unique identification number ofthe data carrier, for example a UID (unique identifier), a PUPI(pseudo-unique PICC identifier, PICC=proximity ICC, ICC=integratedcircuit card) or the like. For data carriers according to ISO/IEC 14443it further holds that a data carrier selected for communication isaddressable during communication via a unique session number(session-ID, CID) allocated dynamically by the reading device. In thisstate such a data carrier no longer responds to the aforementionedsearch signals still emitted by the reading device. In this way thereading device can select further data carriers located in the responsefield via their unique identification numbers and also assign themunique session numbers in turn. According to ISO/IEC 14443, up to 16data carriers can in this way be selected for communication at the sametime and addressed accordingly via 16 different session numbers. Acommand emitted by the reading device and addressed by means of thesession number is then always processed only by the data carrier towhich said session number was assigned.

Further, it is known that a plurality of applications can be located ona portable data carrier at the same time and that the correspondingapplication processes can be executed concurrently when an operatingsystem providing the necessary mechanisms is set up on the data carrier.Concurrent execution of processes means that the latter are executedquasi at the same time by repeatedly toggling between differentprocesses. Toggling between different processes means that saidprocesses are supplied to the processor alternatingly to obtain actualcomputing time. An application process designates an application that isundergoing execution. In the context of this invention, both anapplication and the associated application process will hereinafteralways be designated as an application.

It is possible to address a plurality of different concurrentapplications, for example via their application identifiers AIDs, viadifferent logical channels. Logical channels make it possible to set aplurality of virtual channels in parallel via a single interface by thecorresponding communications protocols being so designed that theaddressed logical channel is also coded. In this way a plurality ofapplications on the data carrier can thus be addressed in parallel viathe application identifier by specification of the particular channel tobe used.

The currently common protocols and the coding of the data to betransferred (APDU, application protocol data unit, a form of datatransfer based on a command/response scheme) allow up to four logicalchannels which are coded by means of two special bits. However, the datacarrier's responses generated upon a command received from outside thedata carrier no longer contain any information about the logicalchannel. This has the consequence that external applications desiring tocommunicate with a plurality of concurrent applications on a datacarrier must be synchronized with each other, since an externalapplication cannot decide by the response of an application of the datacarrier whether it is the response expected by it or is intended foranother external application.

The management of logical channels is very elaborate for an operatingsystem of the data carrier and requires a great amount of memory, allthe more so if communication has to take place under secure conditions,i.e. the data belonging to an application are transferred in encryptedform and are protected in general against spying by other applications.

Problems also occur in cases where a plurality of possibly proprietaryapplications that were hitherto each stored as the only application on aseparate data carrier are now to be integrated on a common data carrierconfigured as a multiapplication data carrier. In addition to theabove-described difficulties in parallel communication, collisions cantake place in the data structures, because the different applicationshave for example hitherto identified different contents on differentdata carriers by identical file identifiers FIDs that now identify onlyone file on the common data carrier. It also happens that applicationsfrom different data carriers are to be integrated that are subject todifferent restrictions in the communications parameters, such as theblock length of transferable blocks.

SUMMARY

It is the object of the present invention to specify a method permittingcontactless communication of a plurality of mutually uncoordinatedapplications of a portable data carrier with a reading device, as wellas an accordingly set up data carrier.

The present inventive method is based on the idea that, for at least twoapplications located on a portable, contactlessly communicating datacarrier that are ready to communicate with a reading device, a firstcommunication-readiness signal to the reading device is generated for afirst of the at least two applications, the signal comprising a firstidentification number assigned to the first of the at least twoapplications and indicating to the reading device the communicationreadiness of said first application, and a secondcommunication-readiness signal to the reading device is generated for asecond of the at least two applications, the second signal comprising asecond identification number different from the first identificationnumber, which is assigned to the second application and indicates to thereading device the communication readiness of said second application.These steps are carried out by an accordingly set up communicationdevice on the data carrier.

The identification numbers perform the role played in the prior art bythe identification number (UID, PUPI and the like) assigned to the datacarrier. The reading device can thus address one application of aplurality of applications located on a data carrier selectively andindependently of the data carrier via the identification number. Acustomary reading device has the impression of communicating withdifferent data carriers.

In this connection it is also possible that the communication-readinesssignals are generated in each case for groups of applications andindicate to the reading device the communication readiness of each ofthe corresponding applications of the particular group. All applicationsin such a group are assigned the same identification number here. It ispossible to assign each of the applications in a group additionalselection information which permits the applications within a group tobe distinguished. In this way the applications can be arranged in ahierarchical manner.

When the communication of an application with a reading device is spokenof hereinafter, this will always mean the communication taking place viaa communication device of the data carrier, whereby the reading deviceselectively addresses said application and the data directed to theapplication are passed on to said application via the communicationdevice of the data carrier. This holds in particular also when the datacarrier has further communication-ready applications located thereon, orapplications that are already communicating with the reading device orhave already been suspended by the reading device after completion ofcommunication.

The signals from the data carrier generated for the applications can bee.g. periodically emitted signals or specific response signals to searchsignals emitted by the reading device. The reading device can thusrecognize which communication-ready applications are located in itsresponse field even when they are stored on a common data carrier.

A toggle functionality present on the data carrier can toggle betweendifferent applications executed on the data carrier concurrently. Inthis way a plurality of applications can be engaged in communicationwith the reading device quasi simultaneously, whereby the togglingbetween said applications permits parallel communication thereof withthe reading device via the communication device. However, thecommunication also can take place consecutively rather than in parallel,adapted to the abilities of the reading device.

The aforementioned restrictions in connection with the use of logicalchannels cease to exist. It is possible for more than four applicationsto communicate with the reading device in parallel. The communicationdevice ensures that all data that are sent to the data carrier by thereading device are processed only by the addressed application. Itensures in particular that all data emitted to the reading device by thedata carrier are so constituted that the reading device can assign themuniquely to one application.

Finally, there results the advantage that a plurality of applicationscan be integrated on a common data carrier independently of each otherand without having to be mutually coordinated, since toggling betweenthe applications allows each of the applications to have its own datastructures, for example a file system, and its own software means, suchas program code only used by it. Collisions with further applicationsregarding these resources are thus ruled out.

The toggle functionality can be configured as part of the operatingsystem. The toggle between different applications can be effected e.g.by branching. In branching, a so-called parent process starts a newprocess, the child process. Both processes, parent and child, use thesame system resources, such as working memory. A toggle can, on theother hand, e.g. also be effected by a context switch by means of adispatcher. Here, the particular process currently assigned to theprocessor is given its own context which comprises for example areas inthe main memory and system variables.

The reading device selects an application for further communication bymeans of the identification number assigned to the application. Theadditional selection information optionally assigned to the applicationcan also be used for selection by the reading device. An applicationselected for further communication is then assigned a session numberdynamically by the reading device. Via said session number theapplication can be addressed uniquely during communication with thereading device. Upon addressing, the session number is so linked in thedata carrier by the communication device with the identification numberassigned to the application and optionally the additional selectioninformation that the correct application is always addressed uponcommunication. When an application has been selected for furthercommunication by the reading device, said communication takes placesubsequently without requiring any further steps. An applicationselected for further communication by the reading device is thus thenengaged in communication with the reading device.

According to the method, the data carrier generatescommunication-readiness signals for one or more applications located onthe data carrier that have not yet been selected for furthercommunication by the reading device even when one or more otherapplications have already been selected for further communication by thereading device and the communication with said other applications is notyet completed. This is preferably also the case after one or more otherapplications have already been suspended by the reading device aftercompletion of communication. A further activity of the applicationsuspended by the reading device on the data carrier, separately from thecommunication with the reading device, is still possible.

While according to the prior art a data carrier engaged in communicationdoes not respond to search signals and a suspended data carrier eithermust first be removed from the response field of the reading device andbe brought back into it to be communication-ready again, or is reset bya RESET signal from the reading device, a reading device can establishcontact with all communication-ready applications of the inventive datacarrier at any time.

The communication device controls the total communication between theapplications and the reading device and always knows the communicationstatus of each application: communication-ready or selected by thereading device for further communication and thus communicating with thereading device or suspended by the reading device after completion ofcommunication.

The data carrier informs the reading device preferably by means ofcollision signals that communication-ready applications that have notyet been selected for further communication are present in the responsefield. Said signals, which are emitted during execution of the collisionalgorithm, can take the form for example of simulated collisions betweena plurality of applications. The reading device will then emit searchsignals in parallel with the communication with other applicationsand/or after the end of communication in order to establish contact withthe applications not yet selected for communication.

The communication device of the data carrier can preferably recognize bythe responses of the reading device to emitted communication-readinesssignals whether the reading device is able to resolve a collisionbetween a plurality of applications. In this connection a termination ofcommunication by the reading device in case more than one data carrieris located in the response field of the reading device can also beinterpreted as a response of the reading device. If the data carrierrecognizes, for example, that the reading device can always process onlyone application in its response field, the emission of furthercommunication-readiness signals can be adapted thereto. The data carrierthereafter emits a communication-readiness signal for an applicationonly when the reading device has completed communication with anotherapplication.

The method preferably stores in a nonvolatile memory, by means of thecommunication device, information about which of the applications waslast selected for further communication by the reading device. Thismakes it possible to ascertain upon reactivation of the data carrier,for example after an interruption of the energy supply, whichapplication last communicated with the reading device, to then generatea communication-readiness signal first for an application differenttherefrom, in order e.g. to prevent the same application from alwaysbeing served first and other applications from possibly having to put upwith long waiting periods or not being executed at all.

The method can therefore be so designed that the reading device cancommunicate with a plurality of applications in parallel. Theidentification numbers assigned to the applications are preferably soselected here that the reading device interprets them likeidentification numbers of different data carriers. The inventive methodcan then be carried out with reading devices according to the prior artwithout any problems.

In the case of reading devices expecting to communicate with MIFAREmemory cards with memories organized in sectors and applications eachfirmly assigned to one of the sectors, it is possible to use theadditional selection information as sector information. Use of thesector information produces a virtual sector assignment of theindividual applications that corresponds to that of a MIFARE memorycard. In this way it is possible to emulate a MIFARE memory card bymeans of a modern data carrier, by a memory of the data carrierappearing to the reading device as a sectored memory by means of thesector information. It is preferably not recognizable to the readingdevice whether a genuine MIFARE memory card is physically present orwhether an inventive emulated MIFARE memory card is involved.

Each sector of such an emulated MIFARE card has exactly one applicationstored therein. Each individual sector is preferably access-protectedseparately for a reading device accessing it, usually by a pair of keysassigned to the sector. It is thus also possible for those applicationsto be stored executably on a data carrier that were assigned tocorresponding fixed sectors on different original MIFARE memory cards.Those applications that were assigned to originally different fixedsectors are preferably then combined into groups with a commonidentification number. The reading device accordingly interprets a thusconfigured data carrier as a multiplicity of MIFARE memory cards,whereby each of said MIFARE memory cards comprises exactly one group ofapplications that reside in pairwise different sectors. In this way thereading device can first select via the identification number a group ofapplications that correspond e.g. to the applications of a singleoriginal MIFARE memory card. Thereafter a special application which wase.g. originally firmly assigned to the sector 1 can be selected on thebasis of the additional selection information in the form of the virtualsector assignment.

The inventive data carrier can be configured in general as acontactlessly communicating chip card, contactlessly communicating labelor contactlessly communicating identification document. Further, it ispossible that the data carrier is configured as a security module SAM(secure application module) in a device set up for contactless datatransmission, the security module having software means forcommunicating contactlessly by means of a suitable interface with thehelp of the device. A SAM is a component secured both mechanically andby software means which serves to store secret data and to executecryptoalgorithms.

Further, an electronic device, in particular a mobile terminal, with acontactless interface for communication with a reading device and with aplurality of access-protected memory areas on different storage media ofthe device can also be designed as an inventive data carrier. Each ofthe memory areas has an application stored therein. The memory areas arepreferably formed on one or more storage media, in particular securechip cards, which are integrated into the mobile terminal. These may befor example (U)SIM mobile communication cards, SD cards (secure digitalmemory cards) or EMV payment cards. EMV designates a specification forpayment cards and is derived from “Europay”, “MasterCard”, and “Visa”.By means of the inventive method it is then possible that the readingdevice communicates with each of the applications on the differentsecure chip cards via the contactless interface of the mobile terminal.The contactless interface is preferably configured as an NFC interface(“near field communication”). This permits a so-called “secure NFC” witha device in the role of a passive communication partner and with aplurality of applications stored thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will hereinafter be explained by way of example withreference to the accompanying drawings. Therein are shown:

FIG. 1 a schematic representation of a first embodiment of an inventivedata carrier;

FIG. 2 a flow chart of a sequence of activities in a first embodiment ofthe inventive method;

FIG. 3 a flow chart of a sequence of activities in a second embodimentof the inventive method; and

FIG. 4 a schematic representation of a second embodiment of an inventivedata carrier.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE DISCLOSURE

Different embodiments of the invention will hereinafter be presented inmore detail. FIG. 1 shows schematically a first embodiment of aninventive data carrier 100 and a reading device 200. The data carrier100 has at least two applications 10, 20, 30 located thereon. The datacarrier 100 comprises a communication device 70 and a toggling device 50that is set up to toggle between the different applications 10, 20, 30.Each of the applications 10, 20, 30 is assigned an identification numberUID1, UID2, UIDn. The identification numbers UID1, UID2, UIDn aremanaged by the communication device 70. When the reading device 200enters into communication with one or more of the applications 10, 20,30 of the data carrier 100, the reading device can select them forfurther communication via the identification numbers UID1, UID2, UIDnand address them in the further course of communication by means ofsession numbers CID1, CID2, CIDn allocated dynamically by it. Saidsession numbers CID1, CID2, CIDn can be linked by the communicationdevice 70 with the identification numbers of the particular applicationsaddressed. All communication between the applications 10, 20, 30 of thedata carrier 100 with the reading device 200 takes place via thecommunication device 70, it being possible to toggle between theapplications 10, 20, 30 by means of the toggling device 50.

FIG. 2 shows a flow chart of a sequence of activities in a firstembodiment of the inventive method. The numbers designate individualmethod steps and states of individual components. When the inventivedata carrier 100, which at the onset is in the non-operational state 0,passes into the response field of a reading device 200, it becomesoperational 1000 and receives a search signal 300 from the readingdevice 200. The communication device 70 of the data carrier 100generates for a first application 10 a communication-readiness signalwhich comprises the identification number UID1 assigned to theapplication 10, 1010. Said signal is emitted by the data carrier, andthe application 10 is selected for further communication by the readingdevice 200 in the course of the selection process 400 by means of ananti-collision method.

While or before the reading device 200 communicates with the application10 of the data carrier 100, 2010, which it addresses via the sessionnumber CID1, 510, it emits further search signals 300, and thecommunication device 70 of the data carrier 100 generates for a secondapplication 20 a communication-readiness signal comprising theidentification number UID2, 1020, and the application 20 is selected forfurther communication by the reading device 200 in the course of theselection process 400. The reading device 200 is now engaged incommunication with the two applications 10 and 20 in parallel, 2010,2020, which are addressed via the session numbers CID1, 510, and CID2,520.

The establishment of communication of the reading device 200 with theapplication 30 follows analogously by a search signal 300, acommunication-readiness signal generated by the communication device 70,1030, a selection step 400, so that the reading device 200 is finallycommunicating in parallel with the three applications 10, 20, 30, 510,520, 530, addressed via the session numbers CID1, CID2, CIDn, 2010,2020, 2030. As indicated, the method can continue with furtherapplications in the same manner.

To the reading device 200 the different applications of the inventivedata carrier 100 appear to be a collection of different data carriersaccording to the prior art.

FIG. 3 shows a flow chart of a sequence of activities in a secondembodiment of the inventive method. The numbers designate, as in FIG. 2,individual method steps and states of individual components. The chiefdifference compared to the embodiment shown in FIG. 2 is that in thepresent example the reading device does not communicate with a pluralityof applications by means of different session numbers at the same time,but with different applications in succession.

Steps and states that are the same as those in FIG. 2 are designated thesame way and will not be explained again. After emission of a searchsignal 300 by the reading device 200, the communication device 70 of thedata carrier 100 generates for a first application 10 acommunication-readiness signal which comprises the identification numberUID1 assigned to the application 1010, and the application 10 isselected for further communication by the reading device 200 in thecourse of the selection process 400 by means of an anti-collisionmethod. The reading device 200 is communicating 2000 with theapplication 10, 610, and completes this communication before it emitsnew search signals. Therebefore the application 10 must be suspended700, for example by means of a DESELECT command, whereby the inventivedata carrier still remains operational 1000 and can thus respond to thenext search signal 300 from the reading device 200 with acommunication-readiness signal generated for a second application 20 andcomprising the identification number UID2 assigned to the application20. An analogous process can now follow sequentially for allapplications located on the data carrier. FIG. 3 also shows thecommunication of the reading device with the applications 20 and 30,620, 630.

The data carrier 100 is preferably set up to recognize whether thereading device 200 is able to handle a plurality of communication-readyapplications located in its response field and to resolve any collisionsoccurring. The data carrier 100 evaluates for this purpose e.g. theresponse of the reading device 200 to communication-readiness signalsemitted in parallel, and thereby recognizes the abilities of the readingdevice 200 for collision handling. A termination of communication by thereading device 200 can also be considered a response, if for example areading device 200 is involved that can fundamentally process only onedata carrier in its response field. If a plurality of data carriers arethen located in the response field, the reading device terminates allcommunication with a data carrier. The data carrier 100 can thus forexample toggle from a method according to the first embodiment to amethod according to the second embodiment if the reading device 200 isnot able to resolve collisions.

The inventive data carrier 100 possesses a further possibility forindicating to the reading device 200 that communication-readyapplications are located in the response field, by the communicationdevice 70 being able to emit signals during the course of ananti-collision method 400 that simulate the collision of at least twodata carriers for the reading device 200. The reading device 200 willthen try to establish contact with such applications at a later time.The signal or data pattern emitted for simulating a collision may bee.g. a code violation (e.g. ISO 14443 type A: Manchester code withsimultaneous sending of a “0” and a “1”) or a checksum error. In thecase of anti-collision methods with several time slots (e.g. ISO 14443type B: slotted Aloha method) the different identification numbers UID1,UID2, UIDn of the applications 10, 20, 30 located on the data carriercan be emitted in different time slots to simulate the presence ofcorresponding data carriers for the reading device 200.

For the reading device 200 there is also the possibility of brieflyswitching off the magnetic field to then, if data carriers without theirown energy supply are involved, after their restart (power-on reset)select a new data carrier in the response field. According to theinvention, the communication device 70 of the data carrier 100 can beset up to store in a nonvolatile memory of the data carrier 100information about which of the applications 10, 20, 30 last communicatedwith the reading device 200, which of the applications 10, 20, 30already completed active communication with the reading device 200, andthe like. With the help of such information it is then possible e.g. togenerate a communication-readiness signal first for an application 10,20, 30 that did not communicate with the reading device 200 last, inorder e.g. to prevent the same application 10, 20, 30 from always beingserved first and other applications 10, 20, 30 from possibly having toput up with long waiting periods or not being executed at all. It isalso possible, however, to first generate a communication-readinesssignal for that application 10, 20, 30 with which the reading device 200actively communicated last, in order for example to bring to an end adata communication that was commenced but not completed.

FIG. 4 shows a second embodiment of an inventive data carrier 100 thatcan emulate one or more MIFARE memory cards MA, MB, MC, MD. MIFAREmemory cards MA-MD possess a memory divided into the sectors FS1, FS2,FS3, FS4, each sector FS1-FS4 having no more than one application storedtherein. Each sector FS1-FS4 is protected against unauthorized accessesseparately by its own key pair, i.e. only a reading device 200possessing the corresponding keys of a sector FS1-FS4 can access thecorresponding sector FS1-FS4 and the data stored therein. It is usualthat special applications on MIFARE memory cards MA-MD are assignedfixed sectors FS1-FS4. The applications are designated in FIG. 410A-40A, 10B-30B, 10C-30C, 40D, the added letter A, B, C, D designatingthe original memory card MA, MB, MC, MD from which the particularapplication 10A-40A, 10B-30B, 10C-30C, 40D was transferred to the datacarrier 100. Thus, e.g. the application 30B is assigned to the sectorFS3 of the memory card MB.

A reading device 200 expecting such a card MA-MD will accordingly onlyread out that sector FS1-FS4 of the memory card MA-MD in which it islooking for the corresponding application 10A-40A, 10B-30B, 10C-30C,40D. If an application 10A-40A, 10B-30B, 10C-30C, 40D is stored on acard MA-MD, but in a sector GS1, GS2, GS3 different from that intendedby the reading device 200, said application 10A-40A, 10B-30B, 10C-30C,40D cannot be found by the reading device 200. For a data carrier 100 tobe able to emulate a plurality of MIFARE memory cards MA-MD or at leasta plurality of applications 10A-40A, 10B-30B, 10C-30C, 40D of MIFAREmemory cards MA-MD that are assigned to the same fixed sector FS1-FS4,the inventive method can be used in different variants which will bedescribed hereinafter.

The data carrier 100 comprises for this purpose a sectored memory 60which is constructed fundamentally like a memory of a MIFARE memory cardMA-MD. In each sector S1-S11 there is stored no more than one of theoriginal MIFARE applications 10A-40A, 10B-30B, 10C-30C, 40D. In anefficient first variant, which is illustrated in FIG. 4, there is notnecessarily a separate identification number UID1-UID3 generated foreach application 10A-40A, 10B-30B, 10C-30C, 40D. It instead suffices ifthose applications 10A-10C; 20A-20C; 30A-30C; 40A, 40D that wereoriginally assigned to the same fixed sector FS1-FS4 are each givendifferent identification numbers UID1-UID3.

The applications 10A-40A, 10B-30B, 10C-30C, 40D stored in the sectorsS1-S11 of the data carrier 100 are divided up into groups G1-G3 eachcontaining only those applications 10A-40A; 10B-30B; 10C-30C, 40D thatwere originally assigned to pairwise different fixed sectors FS1-FS4.Each of said groups G1-G3 is assigned its own identification numberUID1-UID3, and each application 10A-40A, 10B-30B, 10C-30C, 40D withinsuch a group G1-G3 is assigned as additional selection information theoriginally assigned fixed sector FS1-FS4, 10A(FS1)-40A(FS4),10B(FS1)-30B(FS3), 10C(FS1)-30C(FS3), 40D(FS4). Said thus assignedselection information generates a virtual sector assignmentcorresponding to that of an emulated MIFARE memory card.

The communication device 70 now generates communication-readinesssignals for said groups G1-G3 of applications 10A-40A; 10B-30B; 10C-30C,40D, the communication-readiness signal indicating a communicationreadiness of each individual one of the applications 10A-40A, 10B-30B,10C-30C, 40D. The reading device 200 can select such a group G1-G3 ofapplications 10A-40A; 10B-30B; 10C-30C, 40D for communication via theidentification number UID1-UID3. The group in question appears to thereading device 200 to be an original MIFARE memory card MA-MD. Via theadditional selection information FS1-FS4 the reading device 200 can thenselect from the group G1-G3 the corresponding application 10A-40A,10B-30B, 10C-30C, 40D corresponding to that sector assignment GS1-GS3containing the desired application. The selection information FS1-FS4 inthe form of the virtual sector assignment appears to the reading device200 to be a fixed sector assignment of an application on an originalMIFARE memory card. In this variant of the method for emulating MIFAREmemory cards it is possible for the reading device 200 to access allapplications 10A-10C; 20A-20C; 30A-30C; 40A, 40D stored on the datacarrier 100 that were originally assigned to the same fixed sectorFS1-FS4, independently of their actual sector position S1-S11 on thedata carrier 100.

In a second, simpler variant (not shown), each application 10A-40A,10B-30B, 10C-30C, 40D is assigned its own identification numberUID1-UID3. In this way the data carrier 100 appears to a reading device200 to be a multiplicity of MIFARE memory cards MA-MD that all containonly one application 10A-40A, 10B-30B, 10C-30C, 40D in each case. Theinformation about which sector FS1-FS4 the particular application10A-40A, 10B-30B, 10C-30C, 40D was originally assigned to can in turn bestored in the additional selection information assigned to saidapplication 10A-40A, 10B-30B, 10C-30C, 40D.

The communication device 70 of the data carrier 100 thus generatescommunication-readiness signals for all applications 10A-40A, 10B-30B,10C-30C, 40D with different identification numbers UID1-UID3 in eachcase. The reading device 200 can then select and execute an application10A-40A, 10B-30B, 10C-30C, 40D via the corresponding identificationnumber UID1-UID3, provided that the sector assignment FS1-FS4 stored inthe additional selection information matches the sector assignmentGS1-GS3 desired by the reading device 200. The reading device 200 can inthis way separately access each of the applications 10A-40A, 10B-30B,10C-30C, 40D stored on the data carrier 100. Different applications10A-10C; 20A-20C; 30A-30C; 40A, 4D that were originally assigned to thesame fixed sector FS1-FS4 are now all available to the reading device200, independently of their actual sector position S1-S11 on the datacarrier 100. However, it is possible that the reading device 200 selectsfor communication a large number of applications 10A-40A, 10B-30B,10C-30C, 40D that do not correspond to the sector assignment GS1-GS3desired by the reading device 200, since each application 10A-40A,10B-30B, 10C-30C, 40D has been assigned its own identification numberUID1-UID3. However, this increases the total communication effortbetween the reading device 200 and the applications 10A-40A, 10B-30B,10C-30C, 40D on the data carrier 100, so that the method described asthe first variant is generally to be preferred if an efficient datainterchange is desired.

In a third embodiment (not shown), an electronic device, in particular amobile terminal, can be configured as the data carrier 100 forcommunication with a reading device 200. The mobile terminal comprisesfor this purpose a contactless interface, for example an NFC interface.For communication with the reading device 200 the mobile terminalperforms the role of the passive communication partner (“slave”) whilethe reading device 200 functions as the active communication partner(“master”). The applications 10, 20, 30 present on the data carrier 100are each stored in separate memory areas of the data carrier 100,preferably one application 10, 20, 30 per memory area.

The memory areas are located on a plurality of secure chip cards, e.g.(U)SIM mobile communication cards, SD cards, EMV payment cards or thelike, integrated in the mobile terminal. This protects the correspondingapplications 10, 20, 30 and the data generated thereby from unauthorizedaccess. The communication device 70 of the mobile terminal controls thecommunication of the applications 10, 20, 30 on the chip cards with thereading device 200 via the contactless interface. This permits aso-called “secure NFC” between a reading device 200 and a plurality ofapplications 10, 20, 30 stored securely on a data carrier 100.

The invention claimed is:
 1. A method for contactless communication of areading device with at least two communication-ready applicationslocated on a portable data carrier, comprising the steps: generating afirst communication-readiness signal to the reading device for a firstof the at least two applications, the communication-readiness signalcomprising a first identification number which is assigned to the firstof the at least two applications and indicates to the reading device thecommunication readiness of said first application, and generating asecond communication-readiness signal to the reading device for a secondof the at least two applications, the second communication-readinesssignal comprising a second identification number different from thefirst identification number, which is assigned to said secondapplication and indicates to the reading device the communicationreadiness of said second application, wherein the firstcommunication-readiness signal is generated for a first group ofapplications comprising a first plurality of applications including thefirst application, and the first identification number is assigned toevery application in the first group, and the secondcommunication-readiness signal is generated for a second group ofapplications comprising a second plurality of applications including thesecond application, and the second identification number is assigned toevery application in the second group, the first communication-readinesssignal indicating to the reading device the communication readiness ofevery application of the first group, and the secondcommunication-readiness signal indicating to the reading device thecommunication readiness of every application of the second group.
 2. Themethod according to claim 1, wherein each of the applications of thefirst group and/or each of the applications of the second group isassigned additional selection information.
 3. The method according toclaim 1, wherein the reading device emits search signals, the signalsgenerated for the applications comprising response signals to the searchsignals.
 4. The method according to claim 1, including the further stepof toggling between the applications for communication of a selectedapplication with the reading device.
 5. The method according to claim 4,wherein toggling is effected by branching or by context switching. 6.The method according to claim 1, wherein the reading device selects forfurther communication one or more of the at least two applications viathe identification numbers assigned to the applications.
 7. The methodaccording to claim 6, wherein each of the applications of the firstgroup and/or each of the applications of the second group is assignedadditional selection information; and wherein the reading device selectsfor further communication one or more of the at least two applicationsvia the identification numbers assigned to the applications and via theadditional selection information assigned to the applications.
 8. Themethod according to claim 6, wherein for one or more of the at least twoapplications that have not yet been selected for further communicationby the reading device, the communication-readiness signal is generatedwhile the communication with one or more others of the at least twoapplications that have been selected for further communication by thereading device is not yet completed.
 9. The method according to claim 6,wherein for one or more of the at least two applications that have notyet been selected for further communication by the reading device, thecommunication-readiness signal is generated after one or more others ofthe at least two applications have been suspended after completion ofcommunication with the reading device.
 10. The method according to claim6, wherein the data carrier informs the reading device by means ofcollision signals that one or more of the at least two applications thathave not yet been selected for further communication by the readingdevice are present by signals being sent that simulate a collisionbetween a plurality of applications.
 11. The method according to claim6, wherein the data carrier informs the reading device by means of anallocation of one or more time slots that one or more of the at leasttwo applications that have not yet been selected for furthercommunication by the reading device are present.
 12. The methodaccording to claim 6, including the further step of storing informationin a nonvolatile memory of the data carrier about which of the at leasttwo applications has already completed active communication with thereading device.
 13. The method according to claim 6, wherein, upon newcommunication of the reading device with the data carrier, acommunication-readiness signal is emitted first for the application withwhich active communication was effected last.
 14. The method accordingto claim 6, wherein the reading device addresses an application selectedfor further communication via a dynamically allocated session number.15. The method according to claim 14, wherein upon addressing, thesession number is linked on the data carrier with the identificationnumber assigned to the selected application.
 16. The method according toclaim 15, wherein each of the applications of the first group and/oreach of the applications of the second group is assigned additionalselection information; and wherein upon addressing, the session numberis linked on the data carrier additionally with the additional selectioninformation assigned to the selected application.
 17. The methodaccording to claim 1, wherein the data carrier recognizes by a responseof the reading device to communication-readiness signals emitted by thedata carrier whether the reading device is set up to resolve a collisionbetween a plurality of applications.
 18. The method according to claim1, wherein the reading device communicates with a plurality of the atleast two applications in parallel.
 19. The method according to claim 1,wherein the reading device interprets the identification numbers asidentification numbers of different data carriers.
 20. The methodaccording to claim 19, wherein each of the applications of the firstgroup and/or each of the applications of the second group is assignedadditional selection information; and wherein the data carrier generatesthe additional selection information as a virtual sector assignment andthe reading device interprets the additional selection information as asector assignment of a memory area of one of the different datacarriers, whereas the different data carriers may be emulated datacarriers.
 21. The method according to claim 1, further comprising thestep of selecting at least one of the first or second group ofapplications for communication using the respective first or secondidentification number.
 22. A contactlessly communicating portable datacarrier, comprising at least a first and second application storedthereon and a communication device for controlling communication betweena reading device and the at least first and second applications, whereinthe communication device is configured to generate a firstcommunication-readiness signal to the reading device which indicates tothe reading device a communication readiness for the first applicationand a second communication-readiness signal to the reading device whichindicates the reading device a communication readiness for the secondapplication and comprise an identification number assigned to thecorresponding communication-readiness application, wherein the firstcommunication-readiness signal is generated for a first group ofapplications comprising a first plurality of applications including thefirst application, and the first identification number is assigned toevery application in the first group, and the secondcommunication-readiness signal is generated for a second group ofapplications comprising a second plurality of applications including thesecond application, and the second identification number is assigned toevery application in the second group, the first communication-readinesssignal indicating to the reading device the communication readiness ofevery application of the first group, and the secondcommunication-readiness signal indicating to the reading device thecommunication readiness of every application of the second group. 23.The data carrier according to claim 22, wherein the communication deviceis set up to assign additional selection information to each of theapplications of the group.
 24. The data carrier according to claim 22,wherein the communication device is set up to generate thecommunication-readiness signals as response signals to search signalsreceived from a reading device.
 25. The data carrier according to claim22, including a toggling device which is set up to toggle between theapplications of the data carrier for communication of the applicationswith a reading device.
 26. The data carrier according to claim 25,wherein the toggling device is set up to toggle between the applicationsof the data carrier by means of branching or context switching.
 27. Thedata carrier according to claim 22, wherein the communication device isset up to establish the communication between a reading device and anapplication addressed by the reading device via a session number. 28.The data carrier according to claim 27, wherein the communication deviceis set up to link, upon addressing of the addressed application, thesession number with the identification number assigned to the addressedapplication.
 29. The data carrier according to claim 28, wherein thecommunication device is set up to assign additional selectioninformation to each of the applications of the first or second group ofapplications; and wherein the communication device is set up to link,upon addressing of the addressed application, the session numberadditionally with the additional selection information assigned to theaddressed application.
 30. The data carrier according to claim 22,wherein the communication device is set up to determine thoseapplications among the at least two applications that are ready forcommunication with a reading device.
 31. The data carrier according toclaim 30, wherein the communication device is set up to emitcommunication-readiness signals for one or more of the at least twoapplications that are ready for communication with a reading device andnot yet communicating with a reading device while the communication withone or more others of the at least two applications is not yetcompleted.
 32. The data carrier according to claim 30, wherein thecommunication device is set up to emit communication-readiness signalsfor one or more of the at least two applications that are ready forcommunication with a reading device and not yet communicating with areading device after one or more others of the at least two applicationshave been suspended after completion of communication with a readingdevice.
 33. The data carrier according to claim 22, wherein thecommunication device is set up to inform the reading device viacollision signals simulating a collision between a plurality ofapplications that one or more of the at least two applications locatedon the data carrier that have not yet been selected for furthercommunication by the reading device are present.
 34. The data carrieraccording to claim 22, wherein the communication device is set up torecognize by a response of a reading device to communication-readinesssignals emitted by the communication device whether the reading deviceis set up to resolve collisions between a plurality of applications. 35.The data carrier according to claim 22, wherein the data carrier isconfigured as a contactlessly communicating chip card, contactlesslycommunicating label, contactlessly communicating identification documentor as a (U)SIM mobile communication card.
 36. The data carrier accordingto claim 22, wherein the data carrier has a dual interface and can beoperated both contactlessly and with contact.
 37. The data carrieraccording to claim 22, including a memory which is divided into sectors,each of the sectors having no more than one of the at least twoapplications stored therein.
 38. The data carrier according to claim 37,wherein each of the sectors is access-protected separately for access bya reading device to applications stored in said sectors.